Most Active Cookie

This repository processes a cookie log and then returns the most active cookie for that day. This is created through Java, Maven, and Shell script.

Requirements

Given a cookie log file in the following format:

cookie,timestamp
AtY0laUfhglK3lC7,2018-12-09T14:19:00+00:00
SAZuXPGUrfbcn5UA,2018-12-09T10:13:00+00:00
5UAVanZf6UtGyKVS,2018-12-09T07:25:00+00:00
AtY0laUfhglK3lC7,2018-12-09T06:19:00+00:00
SAZuXPGUrfbcn5UA,2018-12-08T22:03:00+00:00
4sMM2LxV07bPJzwf,2018-12-08T21:30:00+00:00
fbcn5UAVanZf6UtG,2018-12-08T09:30:00+00:00
4sMM2LxV07bPJzwf,2018-12-07T23:30:00+00:00

Write a command line program in your preferred language to process the log file and return the most active cookie for specified day. The example below shows how we'll execute your program.

Command:

$ ./most_active_cookie cookie_log.csv -d 2018-12-09

Output:

AtY0laUfhglK3lC7

We define the most active cookie as one seen in the log the most times during a given day.

Assumptions

• If multiple cookies meet that criteria, please return all of them on separate lines.
• You're only allowed to use additional libraries for testing, logging and cli-parsing. There are libraries for most languages which make this too easy (e.g pandas) and we’d like you to show off you coding skills.
• You can assume -d parameter takes date in UTC time zone.
• You have enough memory to store the contents of the whole file.
• Cookies in the log file are sorted by timestamp (most recent occurrence is first line of the file).

Run

Follow the format of the command outlined before:

$ ./most_active_cookie cookie_log.csv -d 2018-12-09

The file must be a .csv file (have a .csv extension label). A sample cookie_log.csv file is provided within the repo. A date (in proper format) should be provided for meaningful computation. JUnit test cases are provided within the repo.